Ado, St., archbishop of Vienne, France, born about 800, made archbishop in 860, and noted for his zeal in reforming the morals of the people and in enforcing Church discipline. He died 875. His memory is celebrated by the Roman Church on Dec. 16. His principal works are a Martyrologium (Paris, 1648, fol.; also, with notes, ed. Georgius, Romae, 1745, 4to) and a
Breviarium Chronicorum de 6 Mundi, AEtatibus (Basil, 1568; also in Bibl. Max. Patr. 16, 768).